Free Electrostatics MCQs with Answers
831 Electrostatics MCQs from Physics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Electrostatics describes forces between charges through Coulomb's law, electric fields and field intensity, then uses electric potential to measure energy per unit charge. Capacitors store charge and electrical energy, with capacitance depending on geometry and dielectric material, not simply on the amount of charge present.
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Read the Electrostatics notesFree MDCAT chapter notes with key terms831 questions · page 3 of 42
- A. 0.63qo
- B. 0.51qo
- C. 0.37qo
- D. 0.9qo
Explanation: In an RC circuit, the time constant (τ) is defined as the time it takes for the charge to reach approximately 63.2% of its maximum value.
Correct answer: 0.63qo- A. Double
- B. Quadruple
- C. Half
- D. One Fourth
Explanation: The energy stored in a capacitor is given by the formula:U = (1/2) * C * V²Where:U is the energy storedC is the capacitanceV is the…
Correct answer: Quadruple- A. Energy = ½ CV
- B. Energy = ½ C2V
- C. Energy = ½ CV2
- D. Energy = ½ C/V
Explanation: The graph of the charge on a capacitor against the voltage across it shows a linear line starting from origin marking a direct…
Correct answer: Energy = ½ CV2- A. ½ µF
- B. 3/2 µF
- C. 5/2 µF
- D. 4/3 µF
- E. 2 µF
Explanation: Recall that the effective capacitance of capacitors in series is the reciprocal of the sum of reciprocals of individual capacitors (just…
Correct answer: 4/3 µF- A. Decreases
- B. Increases
- C. Remains constant
- D. Zero
Explanation: ○The strength of the electric field is reduced due to the presence of dielectric.
Correct answer: Increases- A. To deposit 63% of the equilibrium charge
- B. To deposit 36% of the equilibrium charge
- C. To deposit 63 times of the equilibrium charge
- D. To deposit 36 times of the equilibrium charge
Explanation: q = q°(1-e-t/RC), in the equation RC is the time constant which denotes the time it takes for "63.2% of the charge to be deposited" on the…
Correct answer: To deposit 63% of the equilibrium charge- A. 2.43 x 10^-4 J
- B. 4.86 x 10^-4 J
- C. 2.43 x 10^-2 J
- D. 4.86 x 10^-2 J
Explanation: E = CV^2/2 = QV/2 = 0.5 X 18 X 2.7x10^-6 = 2.43x10^-4 J As this is a numerical so only one option is correct.
Correct answer: 2.43 x 10^-4 J- A. All three capacitors are in series
- B. Two capacitors are in series, one in parallel
- C. Two capacitors are in parallel, one in series
- D. All three capacitors are in parallel
Explanation: When capacitors are connected in parallel, the equivalent capacitance is the sum of the individual capacitances.
Correct answer: All three capacitors are in parallel- A. ½ εᵣ.ε₀.E
- B. ½ ε₀.εᵣ.E2
- C. ε₀.εᵣ.E
- D. ε₀.εᵣ.E2
Explanation: Energy density is the total energy per unit volume of the capacitor, as the electrostatic energy stored in a parallel plate capacitor is…
Correct answer: ½ ε₀.εᵣ.E2- A. 79.5 μC
- B. 35.3 μC
- C. 79.5 pC
- D. 35.3 pC
Explanation: Q = 5.3 x 10^-5 CV = 6.0 VUsing the formula Q = CV, we get:C = Q/V = (5.3 x 10^-5 C)/(6.0 V) = 8.83 x 10^-6FNow, let's find the charge…
Correct answer: 79.5 μC- A. C = εₒA/d
- B. C = dA/εₒ
- C. C = d/Aεₒ
- D. C = dεₒ/A
Explanation: The capacitance of a parallel plate capacitor is directly proportional to the area of the plates (A) and the permittivity of free space…
Correct answer: C = εₒA/d- A. Capacitance remains same
- B. Capacitance becomes double
- C. Capacitance becomes four times
- D. Capacitance reduces to half
Explanation: The formula for capacitance is𝐶=ε𝐴 / 𝑑where,A is the area of the plate, d is the distance between the two parallel plates.If area is…
Correct answer: Capacitance becomes four times- A. increase linearly.
- B. decrease linearly.
- C. increase exponentially.
- D. decrease exponentially.
Explanation: During the charging of a capacitor in an electrical circuit, the charges on the capacitor plates increase exponentially until they reach a…
Correct answer: increase exponentially.- A. increase the capacitance.
- B. decrease the capacitance.
- C. make the capacitance zero.
- D. make the capacitance constant.
Explanation: A) increase the capacitance. Explanation: 1. When a dielectric material is inserted between the plates of a capacitor, the electric field…
Correct answer: increase the capacitance.- A. sum of their individual capacitances.
- B. product of their individual capacitances.
- C. sum of reciprocal of individual capacitances.
- D. product of reciprocal of individual capacitances.
Explanation: When two or more parallel plate capacitors are connected in parallel, their equivalent capacitance is the sum of their individual…
Correct answer: sum of their individual capacitances.- A. 2.5 C.
- B. 5.5 C.
- C. 12.5 C.
- D. 31.5 C.
Explanation: The relationship between charge (Q), capacitance (C), and potential difference (V) across a capacitor is given by the formula:Q = C ×…
Correct answer: 31.5 C.- A. Charge.
- B. Voltage.
- C. Current.
- D. Capacitance.
Explanation: When capacitors are connected in series, the same charge flows through each capacitor, meaning the charge remains constant across all the…
Correct answer: Charge.- A. Metals
- B. Dielectrics
- C. Conductors
- D. Semi-conductors
Explanation: The correct answer is Metals because they have free charges that can move easily. Dielectrics do not have free charges and are insulators.
Correct answer: Metals- A. Time constant.
- B. Electric power.
- C. Electric current.
- D. Applied voltage.
Explanation: The correct answer is Time constant. This concept is fundamental to understanding how quickly a capacitor can charge or discharge in a…
Correct answer: Time constant.- A. Is zero.
- B. Is minimum.
- C. Is maximum.
- D. Cannot be determined.
Explanation: In an electric circuit, when a capacitor is fully charged, it acts as an open circuit.
Correct answer: Is zero.